Prolactin stimulates phosphorylation of the human T-cell antigen receptor complex and ZAP-70 tyrosine kinase: A potential mechanism for its immunomodulation

David W. Montgomery, Joshua S. Krumenacker, Arthur R. Buckley

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26 Scopus citations


Prolactin (PRL) is an immunomodulatory hormone which promotes T-cell activation and proliferation. However, the intracellular mechanisms of this action in normal lymphocytes are unknown. Because the PRL receptor (PRLR) activates several signals also activated by the T-cell antigen receptor (TCR)/CD3 complex, we evaluated whether signaling 'cross-talk' occurs between these distinct receptors. Using human thymocytes, human peripheral blood lymphocytes and the rat Nb2 lymphoma T-cell, we found that PRL induced rapid phosphorylation of multiple, TCR/CD3 complex proteins, an event required for lymphocyte activation. Two of these phosphorylated proteins were identified to be CD3 epsilon and ZAP-70 tyrosine kinase, molecules essential for TCR function. Further, PRL induced tyrosyl phosphorylation of ZAP-70 in each population of T-lymphocytes tested, demonstrating for the first time that ZAP-70 is a target of PRL action. Taken together, our results suggest that the PRLR directly affects T-lymphocyte activation by means of signaling cross-talk with the TCR/CD3 complex.

Original languageEnglish (US)
Pages (from-to)811-814
Number of pages4
Issue number2
StatePublished - Jan 1 1998


ASJC Scopus subject areas

  • Endocrinology

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